Source : Webster's Revised Unabridged Dictionary (1913)

Fossil \Fos"sil\, n.
   1. A substance dug from the earth. [Obs.]

   Note: Formerly all minerals were called fossils, but the word
         is now restricted to express the remains of animals and
         plants found buried in the earth. --Ure.

   2. (Paleon.) The remains of an animal or plant found in
      stratified rocks. Most fossils belong to extinct species,
      but many of the later ones belong to species still living.

   3. A person whose views and opinions are extremely
      antiquated; one whose sympathies are with a former time
      rather than with the present. [Colloq.]

Fossil \Fos"sil\, a. [L. fossilis, fr. fodere to dig: cf. F.
   fossile. See {Fosse}.]
   1. Dug out of the earth; as, fossil coal; fossil salt.

   2. (Paleon.) Like or pertaining to fossils; contained in
      rocks, whether petrified or not; as, fossil plants,
      shells.

   {Fossil copal}, a resinous substance, first found in the blue
      clay at Highgate, near London, and apparently a vegetable
      resin, partly changed by remaining in the earth.

   {Fossil cork}, {flax}, {paper}, or {wood}, varieties of
      amianthus.

   {Fossil farina}, a soft carbonate of lime.

   {Fossil ore}, fossiliferous red hematite. --Raymond.

Source : WordNet®

fossil
     adj : characteristic of a fossil

fossil
     n 1: someone whose style is out of fashion [syn: {dodo}, {fogy},
          {fogey}]
     2: the remains (or an impression) of a plant or animal that
        existed in a past geological age and that has been
        excavated from the soil

Source : Free On-Line Dictionary of Computing

fossil
     
        1. In software, a misfeature that becomes understandable only
        in historical context, as a remnant of times past retained so
        as not to break compatibility.  Example: the retention of
        {octal} as default base for string escapes in {C}, in spite of
        the better match of {hexadecimal} to ASCII and modern
        byte-addressable architectures.  See {dusty deck}.
     
        2. More restrictively, a feature with past but no present
        utility.  Example: the force-all-caps (LCASE) bits in the V7
        and {BSD} Unix tty driver, designed for use with monocase
        terminals.  (In a perversion of the usual
        backward-compatibility goal, this functionality has actually
        been expanded and renamed in some later {USG Unix} releases as
        the IUCLC and OLCUC bits.)
     
        3. The FOSSIL (Fido/Opus/Seadog Standard Interface Level)
        driver specification for serial-port access to replace the
        {brain-dead} routines in the IBM PC ROMs.  Fossils are used by
        most {MS-DOS} {BBS} software in preference to the "supported"
        ROM routines, which do not support interrupt-driven operation
        or setting speeds above 9600; the use of a semistandard FOSSIL
        library is preferable to the {bare metal} serial port
        programming otherwise required.  Since the FOSSIL
        specification allows additional functionality to be hooked in,
        drivers that use the {hook} but do not provide serial-port
        access themselves are named with a modifier, as in "video
        fossil".
     
        [{Jargon File}]